Tony,

It is unfortunate that this thread clearly illustrates the potential problems that can be caused by throwing parts at a problem that you don't understand.

Your blower didn't work, so you changed the Resistor Pack - apparently to the wrong one. The wiring may now be screwed, causing the blower to not work - and this may not even be related to the original problem.

You have changed the head unit repeatedly, without solving the problem.

My suggestion at this point is to stop jumping on your horse and galloping madly off in all directions at once.

If the blower runs on Defrost, the blower works. If there is power on Terminal 87 in the Blower Relay socket, and the blower does not run with the jumper between 30 and 87, there is a problem between Terminal 87 and the blower.

Remove the Resistor Pack. Find Terminal 8 on the Resistor Pack. There should be two black wires on this terminal. Install the Relay Jumper between Terminals 30 and 87 in the Blower Relay socket. Test for 12 vdc on Terminal 8 of the Resistor Pack. Do you have 12 vdc from this terminal to an engine or chassis ground?

(If the pin for Terminal 8 is not in the Resistor Pack, that is wrong. The instructions were to move the connection from Pin 6 to Pin 8. It sounds as if you have removed Pin 8 from the Resistor Pack - that isn't what you were told to do.)

 

Alan as per thread #38 you said to just take out the whole pin 8 and replace it with pin 6 I did that, do I need to cut one of the wire off of pin 8 to make things work correctly?
I took the whole pin out nut the 2 wire that were connected to that opin ar still connected to the pin i have cut mothing of of pin 8 which you say may somehow connect to pin 4 in the loop, but I can tell you that pin 8 is not in the plug of the resiter at all but the wires are still connected to it. You said to cut the pin off once thiongs all worked correctly but I do not get power to 4 pin only to 8 pin which used to be 6 Hve I missed a step some where I reead it all I I fell I did what you tld me to do. All fo the wires and colors are correct in the plug as per the new style resister anyway. The only thing I may have not done is to cut something and I am not sure based on thread 38 I needed to cut anything but maybe I do. If I do pleae let me know.

 

WallyP I did do that and yes there are 2 black wire in pin 8 and I do have voltage there in pin 8 but I do not have it on pin 4 as everyone says I should have. when I jump 30 to 87 blower works fine A/C works fine, but I have no blower speed control I was told to remove the old pin 8 and put 6 in it's place, and I did, here is the color of each pin in the pack presently 1 pin white, 4 pin red, 5 pin white and green, 7 pin white and blue, and 8 pin 2 black wire old 8 pin is sitting on the outside of the pack with the the old wires still connected to the pin.
I think this is correct if not let me know I re-read thread 32 and the instructions and all looks like the instruction said to do, does what I have described to you sound correct? Trust me I don't want to keep throwing things at this problem because as you know things are not cheap. I do not have power to 86 of the relay at all, even when the car is runing and unit is on center position or any position , of course other than defroster far right and also far left which I was told to avoid while testing for power one 86 of the relay. Some how i am not geting power to 86 from anywhere which i was told makes 30 and 87 work. My jumper is very handy as yousaid ans I have it for life. So I think I need to find the problem betwenn 86 and the head or where ever it goes looks like it goes to the head unit to pin 14 of the head unit i could be wrong. but either way i dont get power to 86. I hope I am making some kind of since.

 

This is correct except there should be a red/white wire from pin 4 to pin 8. This is the wire that needs to be cut. Next move the 2 black wires from pin 6 to pin 8.

This is the second issue. Without power to 86 with the relay will not activate...........in other words you'll have no power to 87 and beyond and the blower motor wont work until you jumper 30 to 87.

 

Tony,

You are still on that horse, galloping off in all directions at once. Don't even think about Terminal 86. Forget Terminal 86. If the blower won't work correctly with Terminals 30 and 87 connected, it will never work correctly until you fix the problem between Terminal 87 and the blower motor. Once that end of the circuit works correctly, we can start on Terminal 86.

Get your wiring diagrams out. Look very carefully at the diagram on Page 97-221. Find the box at the top labeled "Resistance Group".

Look at Terminal 6. Forget what you have been told, forget what you have done - just look at the diagram. There are two black wires attached to Terminal 6. One runs to the right and to the blower motor. When you put power on that black wire, the motor runs. The other black wire runs from the left, from Terminal 4 of the Blower Switch. When you put the Blower Switch on Speed 4, you should have battery voltage (12.6 vdc) on the black wire on Terminal 4, which runs to Terminal 6, and from Terminal 6 to the Blower Motor.

Now look at the other end of Terminal 6 in the Resistance Group. That end attaches to a small rectangular block. That is a resistance wire coil. The upper end of the resistance wire coil (resistor) is attached to the little black dot, which is a connection. Down from that connection, the wire attaches to Terminal 7. Terminal 7 connects to a white/blue wire, which connects to Terminal 3 on the Blower Switch. When you put the Blower Switch on Speed 3, power flows from Terminal 3 of the the Blower Switch on the white/blue wire to Terminal 7 of the Resistance Group. From Terminal 7, the power flows thru the resistor and down to Terminal 6, and from Terminal 6 to the blower motor, running the motor at a slightly reduced speed.

Now, look at Terminals 4 and 8. There is a red/white wire connecting these two Terminals.

Study these parts of the circuit until you understand it. If you can't understand it, you probably can't fix the car.

Now, look at the wiring diagram on Page 97-377, and find the Resistance Group. Look at Terminal 6 - there are no wires attached. Look at Terminal 8 - there are your two black wires. There must be power on Terminal 8 for the blower to run.

Now look at Terminal 3 on the Blower Switch. When you put the Blower Switch on Speed 3, power is applied to Terminal 3. This power flows on the same white/blue wire to Terminal 7 of the Resistance Group. Terminal 7 is connected to the top of the resistor on the right end. Power flows thru that resistor (where it is reduced in voltage) to a black dot on the bottom, then back up to a black dot on the right top of the box. Power then flows to the left, thru a thermal switch (the short heavy line with the thermal spring on the bottom) and on left to the end, then down to Terminal 8. The reduced voltage then flows to the blower motor, running it at a slight reduced speed.

Look at Terminals 4 and 8. There is no red/white wire connecting these two terminals.

Study this circuit until you understand it, and then until you understand the differences in the original and the new Resistance Group.

Alan told you:

"On the connector for the resistor pack cut/remove the RE/WT link between pins 4 & 8

Swap the terminal pin connected to the 2 black wires in pin 6 of the connector over to pin 8 of the connector - leave pin 6 disconnected. The terminal pins can be moved in the connector without soldering..."

This meant that you should work on the connector of the wiring harness - not on the Resistance Group.

You said:
"I was told to remove the old pin 8 and put 6 in it's place, and I did, here is the color of each pin in the pack presently 1 pin white, 4 pin red, 5 pin white and green, 7 pin white and blue, and 8 pin 2 black wire old 8 pin is sitting on the outside of the pack with the the old wires still connected to the pin."

If the only wire attached to the old Terminal 8 pin is red/white, that is correct - but that red/white wire will have 12 vdc on it, so it needs to be removed, as Alan suggested.

Hopefully, you now understand the circuit.

Here are the tests that you need to make on the Resistance Group, all with the jumper on Terminals 30 and 87 in the socket of the Blower Relay:
- With the Blower Switch on Speed 0 (all the way down), check for voltage on Terminal 4 at the red wire. Power here flows thru the 2 Ohm resistor, then the 1 Ohm resistor, then the 0.4 Ohm resistor, then the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the lowest speed.
- With the Blower Switch on Speed 1, check for power on Terminal 1 at the white wire. Power here skips the 2 Ohm resistor, but flows thru the 1 Ohm resistor, then the 0.4 Ohm resistor, then the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the next higher speed.
- With the Blower Switch on Speed 2, check for power on Terminal 5 at the white/green wire. Power here skips both the 2 Ohm resistor and the 1 Ohm resistor, but flows thru the 0.4 Ohm resistor, then the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the next higher speed.
- With the Blower Switch on Speed 1, check for power on Terminal 1 at the white wire. Power here skips the 2 Ohm resistor, but flows thru the 1 Ohm resistor, then the 0.4 Ohm resistor, then the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the next higher speed.
- With the Blower Switch on Speed 1, check for power on Terminal 1 at the white wire. Power here skips the 2 Ohm resistor, but flows thru the 1 Ohm resistor, then the 0.4 Ohm resistor, then the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the next higher speed.
- With the Blower Switch on Speed 1, check for power on Terminal 1 at the white wire. Power here skips the 2 Ohm resistor, but flows thru the 1 Ohm resistor, then the 0.4 Ohm resistor, then the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the next higher speed.
- With the Blower Switch on Speed 3, check for power on Terminal 7 at the white/blue wire. Power here skips the 2 Ohm resistor, the 1 Ohm resistor, and the 0.4 Ohm resistor, but flows thru the 0.25 Ohm resistor, then back around the end to Terminal 8, then to the blower motor, making it run at the next higher speed.
- With the Blower Switch on Speed 4, check for power on Terminal 8. Power here skips all of the resistors, flowing straight to the blower motor, making it run on the highest speed.

If the circuit fails any of these tests, you must go back to the wiring diagram on Page 97-221, and find where the power disappears.

I hope that this gives you enough information to fix this part of the circuit, because as Bubba said, "That's all I know about that."

 

Dang Wally you sure type well.

 

But far too much...

 

Nice paragraphs too!

 

WallyP, Thank you first of all for yur help, I beleive I was working with the wiring harnes which i call the plug to the resister pack, my real question is where the red/white wire needs to be cut from pin 4 from old pin 8, it was not connected inside the plug, when i tok the harbesss plug off the the resister proup pin 8 has 2 wires on it or had 2 and it still does but it is not in the plug any longer but the 2 wires are still connected to the pin I have not cut any wire off of the old pin 8 and i think acording to what you are saying is I need to cut the re/white one off of pin 9 that connects to pin 4, I understand all of that but where do I cut it? it was not cinnected to pin 4 iside the plug, do I have to follow the harness wires all the way back until I see where they conect to 4 or can i just cut the wir at the old pin 8 and see if all works which i wanted to do but I thought Alan said I could just take out old pin 8 because i don't need it, so I took it out but i di not cut any wire off of it and I think I need to. there were 2 wires to old pin 8 and the both looked red/white, but I will lokk close maybe only on is red/white and the smaller on is just red. I must assume that the red/white wire on old pin 8 has to be cut off the the pin. or somewhere back inside the harness, I don't think anything based on what i see in the plug for the climate head needs changing so the only thing I am not sure i have done is to cut a wire from old pin 8 that goes to pin for somwhow they connect but where is my question I will cut it off at the pin itself and maybe that will solve my problem of speeds not working I undersatnd the way you dewcrobed the flow and see it on the diagram but where to cut the wire from old 8 to 4 needs to be cut.

 

The education value of this thread is tremendous:

how to read circuit diagrams as they pertain to the 928 Porsche spanning '85 to '89 MYs.

how to understand basic electronincs including relay operation, switches, parallel resistor circuits.

how to alter circuit wiring.

basic electronic troubleshooting.

technical writing simplified for all to 'follow along'.

It certainly has prompted me to have the 2 circuit diagrams in front of me, understand the circuits and realise the wiring changes required.................and my car doesn't have a blower problem.

Come on Tony.............you can do it, just don't burn the car down.

 

Either someone has been there before and swapped the wires around or its wired as the '87 MY (pin 8 has the red and red/white wires to pin 4 which is opposite in the '85 and '86 MY diagrams).

Tony...........what colour of wire is on pin 4 in the original pin configuration?

 

I'm sorry for how bad I type. I try to rush thngs and mis letters/ keys, I will start re reading them before I send them out maybe that will help those who treasure writing skills. You are a great help WallyP. The only 2 pins that had 2 wire to them originally were old 8 pin and the 6 pin in the plug /or harness if you will.
From the looks of the diagram I do see where iit shows a loop from 8 to 4 and it is red/white wire on the left side of the resister group picture, I am not sure which wire to cut off of the old 8 pin so I will cut them both since I do not need the old pin 8 anyway that should break the connection to pin 4, hopefully then things will be ok with my speed controls. I can tell you for sure I have high which is 2 black wires on pin 6 which is now in old pin 8 position on the harness plug that goes to the resister group for the pack.

If I see that one of the wires on old pin 8 is red/white and the other is just red I will leave the red one connected until I make sure I have all of my speeds working. If they all work then time to move on to 86I guess, if not I will just have to find a electrical guy who may understand this more than myself.

I thnk I am doing what you are telling me to do other than when people say cut/remove does that mean cut or remove, or both? Because I can tell you that the old pin 8 is not in the (plug/ resister group) at all but the wires are still connected to it.

Again thanks for your help and patience, I realy am trying even thought it may not seem like it to some.

I am guessing and please correct me if I am wrong the resister group is the plug that fits on the pack correct. So all of my wires are in the correct place but I have failed to cut a wire and I think that is the red/white wire on old pind 8, because I have removed that pin but have not cut anything off of it.

If I solve this I can hardly wait to see what I run into trying to solve 86 on the relay. (G14)

I will let you know what I find out, the car is at home presently or I would do it now and let you know. Oh!!!! Also I hope my spelling and paragraphs are helping.

 

Sorry I've been off this thread a while. if you removed Pin 8 from the plug you don't need to cut anything yet - untill it all works. I think I did say that already... the lack of cutting the wire to the dangling pin affects nothing.

Its just very confusing following what you have done & how. At a certain point you may just be better off getting more experienced help for this.

You must debug the relay socket 87 pin to blower resistor & motor connections.

Blower Relay pin 87 should connect directly to the resistor pack pin 4 (and the now dangling pin 8)

It should also go to Pin 5 of the blower switch.

If these connections are not correct this problem must be solved first.

Alan

 

Tony,
That's a ton of support for you... stay calm. LOL.

 

My friend the scotsman, it looks to be red and white on pin 4 not just red. I only had one wire to pin 4 not 2 wires originally, the old pin 8 had 2 wires, and pin 6 had 2 wires orginally, pin 4 never had 2 wires on it.

Which is why I realy don't know what they mean when they say cut/ remove link fron pin 8 to pin 4. They may be connected somehwere back inside the harness, but they were not inside the plug for the pack.

Either way both wires from old pin 8 are still connected to that pin ,but the pin is not inside the plug at all. I quess I need to cut the wires off the old pin 8 or at least one of them red/white, the same color as my pin 4 originally. Truthfully I am going to re - look over all of the pin colors of pin 4 and 8 as they were originally since I have not cut anything yet all they will be the same as it was. my diagram says theat pin 4 should be red only so I want to make sure of that first. But I think I remeber seeing red and white to pin 4 originally and only one wire not 2.

Thanks again!!!